I understand co-gen with peaking. Some peaking plants are run daily. But how do you do co-gen with standby? Are there standby plants that run frequently enough to make it practical to tap the waste heat?

I'm not aware of any that do this, except in the very narrow instance where one might pipe up a standby generator to throw some of it's waste heat onto an existing thermal loop when it intermittently runs.  I think the article is talking about non-cogen standby and peaking capacity though, recognizing that cogen tends to run baseloaded while those other sources do not.

Fixed.

grist.org

The generation numbers that are being thrown around for global cogeneration, which are to some extent gas and coal fired- are those numbers 1) generation from the entire plant (primary loop and secondary/heat capture)?  Or 2) just the numbers for the additional energy captured from what would otherwise be waste heat?

Just weighing in on this argument over to what extent those numbers unfairly attribute too much of the progress on micropower/DE to coal/gas -

if it's number 1) above, then it is in fact lumping a plant which becomes less dirty (per energy produced), but still significantly dirty, with entirely clean renewables. And so I think that would be misleading on behalf of RMI.  If its 2) above, then the fuel is really just waste heat, and it shouldn't matter if the waste heat originally came from the combustion of coal or dandelions, its power without extra pollution, and so the number is legit to call clean/micropower/RE.  

Sorry I'm a bit short on time and unable to read the 'nuclear illusion' report word for word, but I hope I've extracted the most salient details.

-That said, it appears that much of the high capital costs for new plants are attributed to an inverse economies of scale as new plant construction has slowed dramatically in recent decades... isn't it therefore somewhat unfair to state that as a mature technology it is not prone to much cost reductions?  I understand there most likely won't be a quantum leap as is the potential in, say, solar, but the revitalization of the industry (which would probably require essentially some kind of executive enforcement/encouragement) should bring capital costs further down.

-In looking at just the US's electricity portfolio, a few things jump out at me.  Let's look at where we are now with ~20% nuclear, 50% coal, and the rest a medley of NG, hydro, renewables, etc.  So soon that 20% nuclear will go offline, as many plants are past their expiration date and others will be so shortly.  Let's say we swap in 20% wind (a reasonable ceiling for grid penetration, and even generous as we'll consider reducing that whole pie altogether via efficiency).

That leaves us with our original electricity pie, with a negligible CO2 emission reduction.  Then we factor in efficiency.  This is the most nebulous to me.  Basically I'm skeptical that reducing more than 20% of our current demand will be pretty difficult, and after that will only just keep up with natural energy demand growth (as brought about pop. growth and a more 'electrified' society--i.e. energy demand will plateau at a 20% reduction from current levels).

So let's say we just removed that 20% from the 50% coal pie; awesome. But then let's consider that we want an electrified transportation nation (plug in hybrids, electric light rail, etc.).  I think transport is about 1/3 of total energy usage--or about half as much as electricity production.  I think we can certainly improve efficiency here by a factor of 2, i'll even say 3 (with the combo of less driving, more pub transit, and more efficient vehicles).  But we need to add (0.33 * 0.50 * 100 = 16%) back to our 'electricity pie' that we reduced to 80%; so we're back to 96%.

-I've neglected solar.  I work in solar! I love it! I don't see why 10% will be too difficult; I'll hedge my bets at 10% due to my ignorance of what the combined effect of wind and solar intermittentcy (now we have a combined 30/96 wind/solar fraction) is.

-That leaves us at 86% of our current electricity pie.  I've left out cogen so far.  The two universities I've attended both have cogen plants.  I like it a lot.  But I remain kinda skeptical of how popular it'll ever be in the US.  Simply put, while people might like the idea putting PV panels on their roofs, I'm not sure how they feel about the neighborhood NG plant a mile away, in addition to all the upheaval caused by installation of steam lines, etc.  Furthermore, many geographic places don't need the excess heating. So I'm not gonna factor in much for cogen.  Maybe a few percent--i'll say 4.

-So after all that we have 82% of our current electricity demand; but this necessitates that 32/82 is still from coal power; we've reduced our coal usage by 2*(50-32)% = 36%.  Not bad, but not stellar.  In other words, to get rid of the rest we could use nuclear.  Given my rather thrown-together (but I think pretty reasonable; i think i erred more on the side of enviro-friendly advances) analysis, the next choice to get rid of those coal plants is nuclear (we've saturated wind, solar, etc. (sorry i neglected the always-left out geothermal)).

And so, I'm left to the conclusion that abandoning nuclear doesn't seem like such a good thing, given it could eliminate coal power altogether (with a less-than doubling of it's current energy production in the US).  If someone actually manages to read this, could they be so kind as to where they see my calculations as being far off the mark as to what we can easily achieve?

Thanks

I won't quibble with your numbers really, except to point out that 20% is now from Natural Gas.  Natural Gas is considered relatively "clean" today only because its seen as an alternative to coal.  If you're serious about major reductions in electricity reductions you can't rely too much on that either.  So I'd just bump up your numbers from needing to get rid of that 50% coal part of the pie to needing to get rid of the 70% fossil fuel part of the pie.  Which of course means a greater shortfall that potentially nuclear could help plug.  

And just since you asked about potential advances in nuclear, South Africa is working on a PBMR design (Pebble Bed Modular Reactor).  They key word being Modular - letting them deploy smaller ones (I think around 165MW, which would still be the equivalent of an over 400MW wind farm when you consider capacity factor) and so require less of the major upfront capital.  Also you could start getting revenue from the first few in sequence as you built the rest, to start paying off the capital loans still incurred faster.  And it would use a Helium coolant - inert so it wouldn't turn radioactive, which means safer if it leaks but also less maintenance on the pipes its traveling through (less decay).  And it wouldn't be thirsty for water, which will grow ever scarcer.  So yea there are technological advancements ahead for nuclear.    

nice, I hadn't heard of that out of South Africa.  It always baffles me why they never pushed meltdown proof and un-weaponizable PBRs here in the US--political and diplomatic win-win.

Is this the first commercial scale PBR? (It is to my knowledge)

Greentiger wrote: It always baffles me why they never pushed [...] PBRs here in the US

Each pebble is its own containment, and thus would need separate certification.

OK, I agree with the portion about how it is OK to stack solutions on top of each other on a graph, but I don't understand at all why someone my age or younger would prefer small fossil fuel over any size low-GHG.

Please explain.

Karen Street

It seems strange that Amory Lovins' articles and responses are posted at Gristmill, while David Bradish's articles and responses are only available offsite.

 Nucbuddy, haven't you figured out that David Roberts and Joe Romm only thinks when Amory Lovins gives them permission?  We are talking about world class sycophants, and one would be energy Joe Stalin.  Lovins is all front anyway, and David Bradish is blowing him away.  If you read David Bradish's comments on the way Lovins generates his data, you see that it is all by smoke and mirrors.  

Charles Barton

dude no way are 96 nuc plants gonna be started and completed by 2016.  And even the 36 is site permits applied for (maybe even granted), not started construction.  With maybe a couple exceptions there's not gonna be much coming on line before 2018.  I agree nuc will play an important role after that but let's not overdo it.